Poster abstracts
Poster number 5 submitted by Alecia Biel
Establishing the role of SINE proteins in regulating stomatal dynamics during environmental stresses in Arabidopsis thaliana
Alecia M. Biel (Department of Molecular Genetics, The Ohio State University, Columbus, OH 43210), Iris Meier (Department of Molecular Genetics, Center for RNA Biology, The Ohio State University, Columbus, OH 43210)
Abstract:
Drought is the main contributor to agricultural losses worldwide. The consequences of drought on plants are exacerbated by water loss through the opening of epidermal pores known as stomata. Stomata are formed by pairs of specialized plant cells called guard cells, which regulate pore opening and closing by increasing and decreasing intracellular turgor pressure, respectively. Additionally, stomatal opening allows for the uptake of carbon dioxide (CO2). This CO2 uptake is necessary for photosynthesis, biomass accumulation, and for the release of oxygen. When unregulated, stomatal dynamics can be detrimental to plant health and development.
SINE1 and SINE2 are two outer nuclear envelope proteins forming Linker of Nucleoskeleton to Cytoskeleton (LINC) complexes with Arabidopsis SUN inner nuclear envelope proteins. In wild type plants, the guard cell nuclei predominantly localize at the center of each cell whereas in mutants containing the homozygous sine1-1 allele, the position of the nuclei skew toward a greater distance from the center of the guard cells. Here, we present data that suggest a role for SINE1 and SINE2 in regulating stomatal aperture control under abiotic stress but not biotic stress. Plants lacking either protein show an inability to fully close stomata during ABA-induced drought response but have unimpaired closure during pathogen exposure. Moreover, stomatal opening appears to be compromised under standard growth conditions but can be rescued with exogenous applications of potassium and calcium, suggesting hyposensitivity to these ions. Finally, sine1 mutant plants may have a decreased biomass accumulation. These results implicate that SINE proteins play an important role in regulating stomatal dynamics during abiotic stress. Conversely, biotic stress response may have a separate pathway leading to stomatal closure. Gaining a better understanding of how plants can become drought tolerant and better adapt to environmental stress can be useful not only to improve sustainable food production but also to increase biofuel production on drought susceptible land.
References:
Zhou X, Graumann K, Wirthmueller L, Jones JD, Meier I. Identification of unique SUN-interacting nuclear envelope proteins with diverse functions in plants. J Cell Biol. 2014;205:677-692
Keywords: LINC complex, ABA, Guard Cells